As is well known, it is customary to utilize feather seals that fit into slots formed in the edge of the buttresses of the vanes of the turbine. Heretofore, the slots defining the receptacles for these feather seals were formed by well known electrical discharge machines that are controllable the extent of the slot. Hence, the slot was made so that it did not extend beyond the edge of the side surface. It has been found that improved sealing can be obtained by another method (creep grinding) for fabricating the slot. However, the creep grinding operation inherently requires that the end wall of the slot is penetrated and hence opened leaving a leakage path. Obviously the leakage path had to be sealed and the heretofore method of sealing these ends was to insert a small sheet metal stop that was welded in place. Typically the stop had to be held in place while the welding operations took place. This was a cumbersome and time-consuming operation.
We have found that we can retain the creep grinding operation with its attendant smoother and, hence, better sealing surface by inserting the end of weld wire whose diameter equals the width of the slot and is longer than the depth of the slot and using a laser or electron beam to cut the weld wire at the slot seal surface. The heat generated by the laser serves both to cut and weld the wire into place and hence closing off the end of the slot and thus, eliminating the leakage thereof.